The present invention relates generally to lock cylinders.
Lock cylinders are known in the art and are provided for the locking and unlocking of a latch to permit the opening and closing of a member such as a door or panel.
Oftentimes it is desired that the lock cylinder have the capability of being opened with a master key in addition to a lower level security key. This is particularly true in the case of marine applications where the individual members of a crew need access to individualized areas which the captain of the vessel also needs access to. However, there may be locked areas which are only to be accessible by the captain of the ship. In such cases, the captain would need a high level security key or master key to access his areas and also the crews areas.
In many prior art lock cylinders, the door or panel in which the lock cylinder was installed needed to be as thick as a significant portion of the length of the key which is inserted into the lock cylinder. This resulted in very long lock cylinders which oftentimes would protrude from the back side of the door or panel due to the length of the lock cylinders. Accordingly, due to space limitations it is desired to have a door or closure member which can accommodate a lock cylinder which is thin or in other words where the length of the axis of the lock cylinder is as short as possible so that the lock cylinder when installed in the door does not protrude from the front or back of the door.
A need therefore exists for a lock cylinder having a master key capability which can be accommodated in doors of a thickness which prior art lock cylinders could not be accommodated in.
The present invention has been developed in view of the foregoing and to overcome the deficiencies of the prior art.